(1) Field of the Invention
This invention relates to bicycle wheel drives for conveying motion from pedals to a driven wheel of the bicycle.
(2) Description of the Prior Art
Prior wheel drive mechanisms have generally comprised a large rotatable sprocket on a bicycle and a pair of pedals secured thereto with a chain connecting the pedal carrying sprocket to a driven sprocket on a wheel of the bicycle. Rotation of the pedals by the bicycle rider causes the riders feet engaging the pedals to follow a circular path. The pedals are oppositely disposed so that once in each revolution the pedals are positioned vertically with respect to one another and must be moved from that vertical dead center position to enable force imparted the pedals to be delivered as rotary motion to the driven wheel of the bicycle. Proposals for reciprocal motion of bicycle driving pedals have been made and U.S. Pat. No. 3,891,235 discloses one such proposal wherein pedals attached to a pair of chains, both of which are trained over ratchets incorporating sprockets on the driven bicycle wheel are movable in a vertical reciprocal motion and wherein the motion of the pair of chains reverses with each alternate movement of the pedals attached thereto.
The present invention discloses a substantial improvement over the device of U.S. Pat. No. 3,891,235 for the reason that the chains move continuously in one direction while the pedals and the carriages on which they are mounted reciprocate with ratchet incorporated sprockets on the carriages conveying full downward thrust of the pedals to the chains at all times.